Microsoft has promised to bring the Windows Phone 7.8 update to market early next year for current Windows Phone 7.5 devices, and that new handsets running the software would be sold in the near future around the world

This answers the two key questions concerning the software: when it will land, and what will run it. There has been chatter that certain Windows Phone 7.5 handsets will not receive the update. Microsoft noted in its release that it has to work with individual carriers to have the update tested and approved before it can be rolled out, so the timing of its release will be fluid.

Why would Microsoft continue to vend Windows Phone 7.8 devices? It’s simple, actually: sales volume. The company alludes to this fact by describing the decision as “strengthening the ecosystem by bringing more Windows Phones to more people.” Or: cheaper phones can sell at lower rates, and thus land in more hands.

Microsoft was hit over the weekend by a number of posts from the community – including one from this publication – asking for more information about Windows Phone 7.8; until today, Microsoft had been all but mum on the update since its announcement in late July. The company has now answered those calls.

That current Windows Phone 7.5 users will have to wait, in all likelihood, for early 2013 to have their phones bumped up a software notch isn’t exactly encouraging. The move will leave past Windows Phone owners in the lurch past the holiday season. While this may have the effect of selling more Windows Phone 8 devices, it will certainly lead to certain discomfort among the platform’s early adopters.

One positive point: Through the update, Microsoft claims that it has managed to grow the number of markets where apps can be purchased 30% to 95.